GENUS VIII. 
ATHYRIUM, Roth. 
GEN. CHAR. Sori medial, short, oblong or sublimate, 
attached along the inner side of the venule ; often arcuate 
or horseshoe-shaped and then continued across them. In- 
dusium of the same form as the sorus, opening along the 
side next the mid-vein, its free margin fringed with ca- 
pillary segments, at length reflexed. Veins free mid- 
vein distinct ; venules branched. 
This genus, of which the beautiful Lady Fern is the 
type, is sometimes made to include all the Aspleniums 
having short oblong sori ; others merge it in Asplenium, 
from which, however, those species, with fragile annual 
fronds, and fringed indusia, appear distinct. 
The name is derived from the Greek athyrox, opened; 
in allusion to the turning back of the indusium. 
1. Athyrium rhaetlcum, Roth. Erect Lady Fern. 
Fronds narrow-lanceolate, somewhat rigidly erect, bi- 
pinnate; pinnae distant, convex; pinnules distinct, 
linear acute, deeply pinnatifid, the lobes incurved; 
sori very short and numerous, near the midrib, becoming 
confluent. 
ATHYRIUM RH^TICHM, Roth: Newm. Nat. Aim. (1844), 26. 
ATHYBHJM FILIX-PCEMINA, var. CONVEXUM, Newm. 245: liab. 
Man. 413. ATHYBUM FILIX-F<EMINA, far. BHTICUM, Deakin 
